Removable counter weight for truck cranes



April 6, 1954 A. L. MEYER ET AL REMOVABLE COUNTERWEIGHT FOR TRUCK CRANESFiled Dec. 10, 1951 2 Sheets-Sheet 1 .5 INVENTORS APrll 6, 1954 A. L.MEYER ET AL REMOVABLE COUNTERWEIGHT FOR TRUCK CRANES 2 Sheets-She et 2Filed Dec. 10, 1951 IN V EN TORJ ail, z.

Patented Apr. 6, 1954 UNITED STATEE TENT OFFICE REMGVABLE COUNTERWEIGHTFOR TRUCK CRANES Application December 10, 1951, Serial No. 260,838

6 Claims.

This invention relates to revolving truck cranes and similar apparatushaving booms with sufficient reach to require substantial counterweightand it more specifically resides in an apparatus of this class having amobile undercarriage upon which is mounted a rotatable platform deckthat carries a boom at one end thereof, a gantry frame and machinery forsupport and manipulation of the boom, together with a removablecounterweight received beneath the platform deck at the end thereofopposite the end to which the boom is attached, which counterweightoverhangs the undercarriage upon rotation of the platform to a desiredpredetermined position to permit free uninterrupted vertical descent andascent of the counterweight to and from the ground and work ingposition, and which platform carries hoist and hoist line meansattachable to the counterweight to impart guided vertical movementthereto.

Booms of considerable length and of substantial load capacities areoften employed in cranes and similar apparatus mounted on auto-motivevehicles or other mobile instrumentalities so as to be adapted fortransport over paved highways. In such cranes moments resulting fromboom loads reach such values as to give rise to a need for largecounterweights.

To effect a partial counterbalance it is feasible to mount much of themachinery, carried by the cab, well to the rear of the cab platform.This is seldom sufiicient and additional counterweights of considerablemass must be added to the crane cab at the end opposite that to whichthe boom is mounted. then reaches such values as to exceed wheelloadings permitted by highway authorities. To rem-- edy this undesirableresult, removable counter-- weights which may be transported in separatevehicles have been employed so that the overall weight of the equipmentmay be reduced for the purposes of over the road transport.

It is an object of this invention to provide a removable counterweightfor cranes and the lilre that may be removed, reinstalled and loaded andunloaded to and from separate vehicles with a minimum of difficulty.

It is another object of this invention to provide for a means of removaland reinstallation of a counterweight in which the movement of thecounterweight from and to installed position is substantially vertical.

It is another object of this invention to provide hoisting apparatus foruse in conjunction with a removable counterweight that transmits theload of the counterwei ht during removal and The total weight of largercranes i reinstallation to gantry members that serve as well asanchorage means for the boom stays.

These and other objects and advantages of this invention will appear inthe description to follow. In the description reference is made to theaccompanying drawings forming a part thereof in which there is shown byway of illustration and not of limitation one specific embodiment inwhich this invention may be practiced.

In the drawings:

Fig. 1 is a view in perspective with parts broken away of an instance ofa truck crane in which this invention may be embodied and in which thecab of the crane is shown rotated to the counterweight manipulatingposition,

Fig. 2 is a rear view in elevation with parts broken away and in sectionof the crane cab shown in Fig. 1 with the counterweight raised toworking position,

Fig. 3 is a fragmentary side View in elevation and in section of therear portion of the crane cab shown in Figs. 1 and 2 viewed through theplane 3-3 in Fig. 2 and with the counterweight in lowered position,

Fig. 4 is a top view of one of the guide assemblies carried by thepiston rams of the hydraulic hoists shown in Figs. 1, 2 and 3,

Fig. 5 is a fragmentary side view in elevation of means for securing thecounterweight in raised position, and

Fig. 6 is a top plan view of a counterweight suspending collar thatforms part of the means for securing the counterweight in workingposition.

Referring now to the drawings, there is shown in Fig. 1, a truck crane Iconsisting of a truck chassis 2 that acts as a mobile undercarriage uponwhich is mounted a fully revolvable cab 3 that may be swung to any anglewith respect to the truck chassis 2. The swinging mounting of the cab 3is provided by a roller track 4 secured to the truck chassis 2 in aposition above the axles of the rear wheels 5. Above the roller track 4in supporting relation to the cab 3 is a roller assembly 6. A machineryplatform or deck I forming the base of the cab 3 is mounted directlyupon the roller assembly 6 to provide a support for the machinery andstructural elements that comprise the cab 3.

Extending from the forward end of the cab 3 is an inclined boom 8,pivotally mounted at its lower inner end on the machinery platform I. Agantry or A frame 9 is secured to and extends upwardly from themachinery platform I in known manner, the shell of the cab 3 being shownbroken away in Figs. 1, 2 and 3 to expose portions of the frame 9. Thus,in Fig. 1 the rearward portions of a tension member i9 and a compressionmember i that form a part of frame 9 appear and in Fig. 3 there areshown like portions of a pair of corresponding members l2 and [3. Themembers I9 and H are each secured to a gusset plate M and the members l2and I3 are likewise each secured to a gusset plate |5.

Extending between the plates I4 and I5 is a horizontal cross brace I5that is shown in Fig. 2 and extending downwardly from each of the platesl4 and IE to an attachment with the platform I is a pair of verticaltension members, generally designated by the reference numerals ll andH3. The vertical members it and it serve not only as members of frame 9but are adapted to fulfill an additional function which will be moreparticularly hereinafter described. To complete the supporting structurefor the boom 8, a boom stay in the form of a multiple reaved boom hoistline i9 joins the outer end of the boom 8 with the A frame 9, the linel9 being adapted to be hauled in and payed out so as to elevate anddepress the boom as is desired.

Referring now more specifically to Figs. 2 and 3, it will appear that ahorizontal elevated deck plate 2| extends nearly across the entire widthof the cab 3 and runs forwardly from the rear outer shell 22 of the cab3 to an attachment with a vertical plate 23 secured to two horizontalplates 24 and 25 of the deck proper of platform I. A pair of verticalend plates 23 and 21, welded at the ends of the horizontal deck plate 2complete an open bottomed counterweight housing 28 that is adapted toreceive a counterweight 20. The counterweight housing 28 forms a part ofthe rear of the machinery platform I to which the members l1 and I8 thatform a portion of the A frame 9 are secured by means of angle braces29-29, 3333.

As appears more clearly in Figs. 2 and 4 the vertical member I! is madeup of an outwardly facing channel member 39 and an inwardly facingchannel member 3| that are spaced from one another to form a shaft. Abrace 32 spaces the channels 30, 3| near the top thereof and the channel3| extends above the brace 32 to connect to the gusset l4. In similarfashion member I8 is formed of an outwardly facing channel member 34 andan inwardly facing channel member 35 that are spaced to form a similarshaft. An upper cross brace 36 spaces the channels 34, 35 from oneanother and the channel 35 extends upward to connect to the gusset |5.

Secured to the underside of each of the cross braces 32 and 36 is one ofa pair of hoist support brackets 31. Passing horizontally through thebrackets 31 and the respective vertical channel members 30, 3| and 34,35 that flank the brackets 37 are a pair of mounting pins 39 that carrydownwardly hanging reciprocating hydraulic hoist motors 39 and. 4-9. Theleft side hoist motor 39, as viewed in Fig. 2 is disposed in the shaftbetween the spaced channels 30, 3| and the right hand hoist motor 40 isdisposed in like manner in the shaft between the channels 34, 35.Forming the body of each of the hoists 39, 40 is a cylinder 4! that ispivotally fastened at its upper end to the respective pin 39 and carriedin each cylinder 4| is a piston ram 42 that may be extended downwardlyand retracted upwardly with respect to its associated cylinder 4|. Alsocarried upon the pins 38 are sets of loosely mounted freely rotatablesheaves 43 which serve as hoist line reaving guides.

A hydraulic actuating system, for the operation of the hydraulic hoistmotors 39, 40 includes a control unit 45 containing a pump and. sump forhydraulic fluid, which is mounted on a shelf 44 secured to verticalchannel 35. An inlet-outlet pipe 68 extends from the base of the unit 45and terminates in a T connection 69 at its opposite end. Joined to theconnection 69 are a pair of independently operable control valves 10that provide for a control of the fluid flow in hydraulic fluid lines 46that lead from each of the valves in to the upper head of each of thecylinders 4|. A control lever 43 on the control unit 45 is movable to aposition in which fluid is forced by pump action into the cylinders 4|to force the piston rams 42 downwardly in unison, movable into anotherposition in which fluid is locked in the cylinders 4|, and movable to aposition in which fluid is permitted to flow in a reverse direction intothe sump at a controlled rate of flow. In event that it is desired notto move the rams 42 in unison the appropriate valve 10 may be closed andoperation of the lever 4! will affect movement of the chosen ram 42.

Secured to the lower end of each piston ram 42 is a collar 41 whichbears against and is rigidly joined to a vertical travel guide assembly,generally designated by the numeral 48, as appears more clearly in Figs.3 and 4. As shown therein the assemblies 48 ar made up of a pair of sideplates 49 that extend between and overlap a portion of the channelmembers 34, 35, the plates 49 being spaced from one another by a pair ofend plates 58 and a pair of through bolts 5|. A top plate 52 throughwhich the piston ram 42 passes and a bottom plate 61, shown in Fig. 3,that abuts the bottom end of the ram 42 extend between the end plates 50to complete a box like frame for the guide assembly 48. Carried by theframe of the assembly 48 is a horizontally disposed pin 53 that extendsthrough the side plates 49 and the piston ram 42. Mounted on the pin 53so as to rotate freely is a sheave 54 disposed alongside one of the sideplates 49 and near the opposite plate 49 the pin 53 carries a becketthimble 55.

Each of the thimbles 55 serves to anchor an end of one of a pair ofhoist lines 58 to a re.- spective guide assembly 48, one of which hoistlines 53 is associated with the left hand hoist and reaving sheaves 43carried by the vertical tension member I7, and the other of which hoistlines 55 is associated with the right hand hoist and reaving sheaves 43carried by the member iii. Each hoist line 56 extends upwardly from itsrespective thimble 55 toward the upper sheave set and thence over asheave 43 and downwardly toward the respective guide member 48 to passabout the respective sheave 54 and again upwardly. The lines 56 thenpass about the remaining upper sheave 43 and drop downwardly toterminate in live end portions 5! that are in alignment with openings 59in the deck plates 2 i. The openings 58 permit the live end portions 51to pass into and through the counterweight housing 29 as the hoist lines53 are paid out or drawn in in response to hoist action. That portion ofeach of the hoisting lines 56 that extends between and passes over theassociated sheaves 43, 54 to the thimble 55 may be termed a wind lassportion 59. The number of parts of hoist line that comprise the Windlassportion 59 determine the mechanical advantage and the distance of ascentor descent of the live end portion 51 for a given movement of theassociated piston ram 42. As a piston ram i2 is extended outwardly fromits associated cylinder 56 the guide member 48 carried at the endthereof is slideably guided by the vertical channels between which it isembraced and the live end 5! is drawn upwardly. A reversed motion of theram 42 shortens line stored in the windlass portion 59 and the live endportion 5'! is payed out.

A counterweight 29, formed in any convenient manner, preferably as asingle continuous mass is provided of such size and configuration as tobe received within the open bottomed housing 28 when lifted to raisedposition as shown in Fig. 2. Embedded within and extending verticallythrough and above the counterweight 2!) are a pair of lifting rods 69spaced to align with the live end portions 51 of the hoist lines 56 andwith the openings 58 in the deck plate 2! through which the lines 56 maybe extended. Mounted on each of the upward extensions of the rods 5!) isone of a pair of counterweight suspending nuts 6| that are in freethreaded engagement with the rods 65! so as to admit verticaladjustment. Threadingly secured to the top of each of the rods 58- isone of a pair or" shackles 62 provided with removable pins 63-ii3 whichpass through the clevis portions thereof. The pins 53 of the shackles 62engage thimbles 53 in eyes 64 formed at the live ends 5? of therespective hoist lines 56. By removal and insertion of the pins 63 thecounterweight 253 may be detached from and attached to the hoistingapparatus.

Fastened securely to the deck plate ii are a pair of reinforcing braceplates 555 that cover the areas of the deck plate 2! in the closevicinity of the two openin s 53 which pass through not only the deckplate 2! but the respective reinforcing lates es as well. Adapted to beplaced atop the two reinforcing lates $5 are a pair of slotted l collarsc5 of a confi uration as shown in Figs. 5 and 6. The base diameter ofthe collars 68 is greater than that of the openin s 58 and by placingthe collars 65 each over an opening 58 with the slots thereof receivingthe respective rods 68 that have been passed upwardly through therespective openin s 58 the openings are blocked so as to preventdownward movement of the nuts 5!. In this way the counterwei ht as maybe supported not by the hoisting apnaratus but by the deck plate 2! thatforms a portion of the i machinery platform 1.

Thus the counterweight 20 may be secured within the housing 28 duringthe periods of crane operation. with the weight being borne on the nutsiii and the collars 65 as shown in Fig. 5.

The hydraulic hoist apparatus in this condition is not required tosuspend the weight 23. By turning the nuts a! downward. thecounterweight 25} may be raised until the top thereof abuts theunderside of the deck plate 2! eliminating looseness, as shown in Fig.2.

To lower the counterweight 2!! the cab s is rotated to such a positionwith respect to the truck chassis 2 that the housing 23 and the weight 2overhang beyond the chassis 2. One such position is shown in Fig. 1wherein the counterweight 2b is shown lowered below the housing 28.

With such an overhang it becomes possible to raise and lower thecounterweight 2!! with a direct movements of the weight is eliminatedand handling of the weight may be accomplished with case.

In lowering the weight 20, after the rotation of the cab 3 to anoverhanging position, the nuts Si are first turned to raise them thustransferring the counterweight load to the hoist lines 56. The collars'65 are then removed from the openings 53 and by operation of thehydraulic system the piston rams G2 are contracted to within the hoistcylinders it to efiect a paying out of the windlass portions as of thehoist lines 56. The live ends 5? of the hoist lines 56 are thus extendedand the weight 20 will emerge from the housing 28 and will be lowered tothe pavement. By unshackling the removable pins 63 from the thimbles Mthe weight is freed of the hoist apparatus and may be dealt with as aunit separate from the truck crane I usually with the aid of the craneboom itself.

As the weight 20 is raised and lowered by the hoist lines 56 the load issupported by the vertical members H and it acting in compression. Thechannels 31 and 34, of the members I! and. it} are preferablyprestressed under a tension during assembly of the A frame 9 prior toplacing of load thereon. In this way working distortion of thecantilever truss that is formed by the platform l and the A framemembers leading forwardly from the upper ends of the members l1, it isminimized. When it is desired to raise or lower the counterweight 2a theboom 8 is not loaded and the stress on the members ll, it imposed by theboom a is relatively small. Therefore. the vertical members I7, I 8 arenot then impaired their ca acity to sustain the loading imposed thereonby the hoisting of the counterweight 28.

We claim:

1. In an apparatus of. the class described an automotive chassis, arotatable machinery platform mounted upon aid chassis including acounterweight supporting portion at one end having a adapted to pass ahoist line therethrough. a counterweight shaped to be received inworking position beneath said supporting portion of said platform foruninterrupted vertical descent therefrom upon rotation of said p atformto a predetermined position, hoisting means carried by said platformincluding a hoist line guide disposed above the gap in said supportingportion of said platform, a counterweight hoist line having a live endadapted to be drawn in and payed out by said hoisting means extendingdownwardly from said hoist line guide for passage through said gap insaid supporting portion of said platform. connecting means for joiningthe live end of said hoist line to said counterweight having a flangespaced upwardly from said counterweight of dimension to pass throughsaid gap, and a collar having a dimension greater than that of said gapbeing adapted to be positioned over said gap to rest upon saidsupporting portion of said platform and beneath said flange to blockpassage of said flange through said gap.

2. In an apparatus of the class described an automotive chassis, arotatable machinery platform mounted upon said chassis. an open bottomedcounterweight housing at one end of said platform forming a part thereofand having a counterweight supporting portion, a counterweight shaped tobe received in working position by said housing, said counterweight whenin working position overhanging said chassis for uninterrupted verticaldescent upon rotation of said platform :to an overhanging position,hoisting means carried by said platform including a pair of :hoist lineguides disposed above said counterweight housing, a pair ofcounterweight hoist lines each joined to and adapted to be drawn in andpayed out by said hoisting means, each of said hoisting lines extendingrespectively downwardly from one of said respective hoist line guides toa vertically moveable live end for connection with said counterweight, apair of connecting means for joining the live ends of said hoist linesto said counterweight each including a sidewardly extending flangespaced above said counterweight supporting portion of said housing whensaid counterweight is received in working position by said housing, anda removable collar means adapted to rest upon said supporting portionand beneath said flanges to block descent of said flanges and connectingmeans for supporting said counterweight in working position.

3. In an apparatus of the class described an automotive chassis, arotatable machinery plat form mounted on said chassis, a tiltable boommounted at one end of said platform, a boom supporting gantry risingfrom and carried by said platform including a pair of normally tensionedvertical members secured at the end of said platform opposite the end towhich said boom is mounted, a counterweight shaped to be received inworking position beneath said platform and below said vertical membersadapted to be raised to and lowered from working position, hoist meanscarried by said platform, a pair of hoist line reaving guide member setseach respectively including an anchoring member and a verticallymoveable guide engaging a respective vertical member for guided ascentand descent joined to said hoist means to be raised and lowered thereby,a pair of counterweight hoist lines each respectively carried by arespective guide inember set, each hoist line being secured at one endto the respective anchoring member and extending therefrom between andabout the respective reaving guide members to form a windlass portionand leading from said Windlass portion to a vertically falling live end,a pair of connecting means each for joining the live end of one of saidhoist lines to said counterweight and .having a threaded shank with asidewardly extending flange threadedly secured thereto, and a removablecollar for each of said connecting means adapted to rest upon saidplatform and beneath the respective flange to block descent of theflange and associated connecting means to support said counterweight inworking position.

4. In an apparatus of the class described a mobile undercarriage, arotatable machinery platform mounted on said chassis, a tiltable boommounted at one end of said platform, a boom supporting gantry risingfrom and carried by said platform including a pair of transverselyspaced vertical members secured at the end of said platform opposite theend to which said boom is mounted, a counterweight shaped to be receivedin working position beneath said platform and below said verticalmembers adapted to be raised to and lowered from working position, apair of independently operable hydraulic hoists each joined to the upperextremity of said vertical members and comprising a cylinder and apiston ram extendable and retractable with respect to the cylinder, aset of hoist line reaving guide members for each of said hoists each setincluding an anchoring member and a vertically moveable guide confinedto vertical ascent and ing joined to said piston rams of said hydraulichoists, and a counterweight hoist line for each of said hoists carriedby said reaving guide members and each secured at one end to therespective anchoring member and extending therefrom between and aboutthe respective reaving guide members to form a Windlass portion andleading from said Windlass portion to a vertically falling live endcoupled to said counterweight.

5. In a removable counterweight for a crane the combination comprising amachinery "platform having a deck plate with an opening therein adaptedto pass a hoist line therethrough, a counterweight shaped to be receivedin working position beneath said platform and below said opening, ahoisting rod fastened to and extending upward from said counterweightadapted to extend through said opening when said counter weight is inworking position, a hoist, a hoist line running from said hoist to adetachable connection with said rod adapted to be drawn up and paid outin response to said hoist, a weight suspending nut threadedly secured onsaid rod and of dimension to pass through said opening, and a collarhaving a dimension greater than that of said opening, said collar beingadapted to be positioned over said opening and beneath said nut to blockpassage of said nut through said opening.

6. In an apparatus of the class described a mobile undercarriage, arotatable machinery platform mounted on said chassis, a tiltable boommounted at one end of said platform, a boom supporting gantry risingfrom and carried by said platform including a pair of transverselyspaced vertical members secured at the end of said platform opposite theend to which said boom is mounted, a counterweight shaped to be receivedin working position beneath the end of said platform from which saidvertical members rise adapted to be raised to and lowered from workingposition, a pair of hydraulic hoists each joined to one of said verticalmembers and comprising a cylinder ranged alongside the respectivevertical member and a piston ram extendable and retractable therefromalongside the respective vertical member, a set of hoist line reavingguide members for each of said hoists each set including anchoring meansand a vertically mov able guide confined to vertical ascent and descentby slidable engagement with the associated vertical member, said guidesbeing joined to said hoists for movement in response to extending orretracting movement of said rams and to guide movement thereof, and acounterweight hoist line for each of said hoists each secured at one endto one of said anchoring means and extending between and about therespective reaving guide members and leading therefrom to a verticallyfalling live end coupled to said counterweight.

Luebbers Jan. 28, 1947

